2-piperidino-3-phenylquinoxaline compounds

ABSTRACT

AND ITS ACID ADDITION SALTS, WHEREIN R, AS ABOVE, REPRESENTS HALO OR METHYL, SAID R BEING LOCATED ON THE 6 OR 7 POSITION, ONLY, AND N REPRESENTS AN INTEGER OF FROM 0 TO 1, BOTH INCLUSIVE. THE PRESENT INVENTION IS CONCERNED WITH METHODS AND COMPOSITIONS USEFUL IN INHIBITING THE GROWTH OF PLANTS, AND IS PARTICULARLY DIRECTED TO METHOD EMPLOYING AND COMPOSITIONS COMPRISING AN ACTIVE AGENT WHICH IS A COMPOUND OF THE FORMULA   2-R&#39;&#39;,3-PHENYL,(R)N-QUINOXALINE   OR ITS ACID ADDITION SALTS, WHEREIN R REPRESENTS HALO OR METHYL, SAID R BEING LOCATED ON THE 6 OR 7 POSITION, ONLY; R&#39;&#39; REPRESENTS HALO, HYDROXY, LOWERALKOXY, AMINO, N-LOWERALKYLAMINO, DI-N-LOWERALKYLAMINO, OR PIPERIDINO; AND N REPRESENTS AN INTEGER OF FROM 0 TO 1, BOTH INCLUSIVE. THE PRESENT INVENTION IS ALSO DIRECTED TO THE NOVEL COMPOUND OF THE FORMULA   2-PIPERIDINO,3-PHENYL,(R)N-QUINOXALINE

United States Patent 3,647,793 2-PIPERIDINO-S-PHENYLQUINOXALINECOMPOUNDS Quentin Francis Soper, Indianapolis, Ind., assignor to EliLilly and Company, Indianapolis, Ind.

No Drawing. Original application Mar. 22, 1968, Ser. No. 715,144, nowPatent No. 3,582,315. Divided and this application Nov. 5, 1969, Ser.No. 871,035

' Int. Cl. C07d 51/78 U.S. Cl. 260-250 R 2 Claims ABSTRACT OF THEDISCLOSURE The present invention is concerned with methods andcompositions useful in inhibiting the growth of plants, and isparticularly directed to methods employing and compositions comprisingan active agent which is a compound of the formula i E-R' or its acidaddition salts, wherein R represents halo or methyl, said R beinglocated on the 6 or 7 position, only; R represents halo, hydroxy,loweralkoxy, amino, n-loweralkylamino, di-n-loweralkylamino, orpiperidino; and n represents an integer of from 0 to 1, both inclusive.

The present invention is also directed to the novel compound of theformula and its acid addition salts, wherein R, as above, representshalo or methyl, said R being located on the 6 or 7 position, only, and nrepresents an integer of from 0 to 1, both inclusive.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisionalapplication of my 00- pending application Ser. No. 715,144, filed Mar.22, 1968, now Pat. No. 3,582,315.

DETAILED DESCRIPTION OF THE INVENTION As above set forth, the presentinvention is concerned with methods employing and compositionscomprising an active agent which is a compound of the formula 3,647,793Patented Mar. 7, 1972 ICC or its acid addition salts, wherein Rrepresents halo or methyl, said R being located on the 6 or 7 position,only; R represents halo, hydroxy, loweralkoxy, amino, n-loweralkylamino,di-n-loweralkylamino, or piperidino; and n represents an integer of from0 to 1, both inclusive.

The present invention is also directed to the novel compound of theformula loweralkyl For the purposes of the present invention, eithertautomeric form of such compounds can be utilized, or the compound canbe employed as a mixture.

All of the compounds to be employed as active agent in accordance withthe present invention are prepared by known procedures, and many of thecompounds are commercially available.

In a first method, suitable for preparation of those compounds whereinR"represents hydroxy, a phenylenediamine of the formula is reacted withbenzoylformic acid;

HOJLL The reaction, conveniently conducted in an inert liquid reactionmedium and at reflux temperatures, results in the preparation of thecorresponding 2-hydroxy-3-pheny1- quinoxline. Such compounds can beconverted to corresponding 2-halo compounds by the method of Shiho etal., (Chemical Abstracts, 56, 1453b [1962]) wherein, in thepreparation-of 2-chloro-3-phenylquinoxaline, 2-hydroxy-3phenylquinoxaline was refluxed with POCl For preparation of thosecompounds wherein R represents amino, loweralkylamino,diloweralkylamino, or piperidino, the corresponding2-hal0-3-phenylquinoxaline is reacted with a suitable amine to obtainthe corresponding Z-amino, loweralkylamino, diloweralkylamino, orpiperidino compound. The reaction requires the presence of a hydrogenhalide acceptor for good results.

In a representative example, 7.2 grams of 2-chloro-3- phenylquinoxaline(0.03 mole) is added to and mixed with sodium hydroxide (1.2 grams; 0.03mole), piperidine (2.5 grams; 0.03 mole), and 25 milliliters ofdimethylformamide. The mixture is refluxed for several hours, withstirring, and then permitted to cool and poured onto ice. The2-piperidino-3-phenylquinoxaline typically separates as a yellow gum; itis separated, washed with water, dried,

and recrystallized from petroleum ether. In a representative operation,the product obtained melted at 824 C and its structure was confirmed byNMR analysis.

Also, the 2-halo, especially 2-chloro compounds, can be used as startingmaterials to prepare the corresponding 2- loweralkoxy compounds. SuchZ-halo compound is reacted with an alkali metal loweralkoxide,preferably in the same loweralkanol as solvent. The tautomers can beseparated in known chemical procedures. Thus, for example, the mixturecan be subjected to hydrolysis whereupon the reacting 2-loweralkoxytautomer will be converted to the corresponding Z-hydroxy compound whichcan, in turn, be separated from the non-reacting 1-loweralkyl-3-phenyl-2(1H)-quinoxalone tautomer. Chromographic separation can also beemployed, especially for small quantities.

Representative compounds to be employed in accordance with the presentinvention include:

2-chloro-3-phenylquinoxaline 2-bromo-3-phenylquinoxaline2-iodo-3-phenylquinoxaline 2-amino-3-phenylquinoxaline2-hydroxy-3-phenylquinoxaline 2-ethoxy-3-phenylquinoxaline2-fluoro-3-phenylquinoxaline 2-methylamino-3-phenylquinoxaline2-n-propylamino-3-phenylquinoxaline 2-dimethylamino-3-phenylquinoxaline2-diethylamino-3-phenylquinoxaline 2,6-dichloro-3-phenylquinoxa.line2-chloro-7-methyl-3-phenylquinoxaline2-hydroxy-7-bromo-3-phenylquioxaline2-amino-6-fluoro-3-phenylquinoxaline2-methoxy-6-iodo-3-phenylquinoxaline2-piperidino-6-chloro-3-phenylquinoxaline2-piperidino-7-methyl-3-phenylquinoxaline2-dimethylamino-6-chloro-3-phenylquinoxaline2-piperidino-7-bromo-3-phenylquinoxaline 2-chloro-3-phenyliquinoxalinehydrochloride 2-hydroxy-3-phenylquinoxaline acetateZ-piperidino-3-phenylquinoxaline hydrochloride 1-rnethyl-3 -phenyl-2( 1H-quinoxalone 2-piperidino-6-methyl-3-phenylquinoxaline2-sec-butoxy-S-phenylquinoxaline2-piperidino-6-fiuoro-3-phenylquinoxaliue 1-ethyl-7-chloro-3-phenyl-21H) -quinoxalone 2-piperidino-7-iodo-3-phenylquinoxaline Thecompoundsserving as active agent in accordance 4 theirselective'pa'ttern of"activity',' which'is' exhibited at lower rates,especially when employed in preemergent application. At such lowerrates, defined more completely hereinbelow, the compounds are capable ofeliminating from a crop area weed grass seeds and emerging seedlings aswell as many broadleaf weed plants of varying ages, while leavingunharmed the crop. Crops from which weeds can be removed by thisselective application of the present invention include cotton, corn,soybeans, and the like.

However, those of the agents wherein R represents piperidino, which aretaught and claimed herein as new compounds, exhibit a different patternof activities. They exhibit, as the rest of the compounds to be employedin accordance with the present invention, selective activity inpreemergent application. But they are active in postemergentapplication, although with little selectivity, at rates below thoserates at which the rest of the compounds to be employed as active agentare elfective.

In its broadest sense, the present invention is directed to a methodwhich comprises applying to a plant part, which can be a seed or othersimilar reproductive unit of a plant, a growth-inhibiting amount of theactive agent of the present. invention. In a preferred embodiment, thepresent invention is directed to a method for inhibiting the growth ofweeds in an area seeded or planted to a crop plant which comprisesapplying to the area an amount of active agent which inhibits the growthof weeds Without causing substantial harm to the crop plant.

It is not critical to the practice of the present invention thatcomplete destruction of undesirable vegetation be obtained, it beingadequate if the growth of the unwanted vegetation is merely inhibited.Especially in the practice of the present invention for obtainingselective action, inhibition falling short of actual killing isadequate, particularly when combined with naturally-occurringconditions, such as limited moisture and the like, which more adverselyaifect the vegetation selectively inhibited than the crop plant.

The compounds serving as active agent in accordance with the presentinvention are suited to a wide variety of herbicidal applications. Thus,for example, at rates which evoke the selective action of the compounds,which rates are defined more completely hereinbelow, the compounds canbe used as selective herbicides in crop plants, such as, for example,cotton, corn, sorghum, soybeans, and the like. In such use, applicationcan be made preemergent to both crops and weeds, or, preferably by meansof a directed spray application technique, postemergent to the cropplant but both preemer-gent and postemergent to the weeds. In anotherapplication, the compounds can be used to give broad herbicidal actionon non-crop plant land, including intermittently non-crop strips ofcontour-farmed land. For such usage on socalled fallow land, applicationcan be made in spring to suppress vegetative growth until a fall orfollowing spring planting, or in the fall to suppress vegetative growthuntil a spring or following fall planting. Furthermore, in an otherapplication, the present compounds can be utilized to control weeds intree crop plantings, such as plantings of the various citrus trees. Inthese latter types of applications, the present compounds areparticularly advantageous because of the relatively rapid disappearanceof their herbicidal effect, thereby permitting subsequent crop plantingsas in the instance of contour farming, and avoiding buildup in the soil.

Thus, in particular embodiments, the present invention is directed to amethod for inhibiting the growth of weeds in an area seeded or plantedto a crop plant which comprises applying to the area an amount of activeagent which inhibits the growth of weeds without causing substantialharm to the crop plants, wherein the crop is (a) corn, (b) soybeans, or(c) sorghum.

In yet another particular embodiment, the present invention is directedto a method for controlling the growth of vegetation in fallow landwhich comprises applying to such land an effective amount of the activeagent of the present invention.

The practice of the present invention in any of its numerous embodimentscan in some instances be carried out with unmodified compound; however,for good results, it is generally necessary that the compound beemployed in modified form, that is, as one component of a compositionformulated to implement the plant growth inhibiting effects. Thus, forexample, the active agent can be mixed with Water or other liquid orliquids, preferably aided by the usage of a surface active agent. Theactive agent can also be incorporated on a finely-divided solid, whichcan be a surface active substance, to yield a wettable powder, which cansubsequently be dispersed in water or other liquid, or a dust which canbe applied directly. Other methods of formulation are known in the artand can be employed in implementing the present invention.

In carrying out the novel method of the present invention, the exactamount of the active agent employed is not critical and will vary,depending upon the type of growth-inhibiting effect desired, theidentity of the plants concerned, the particular active agent used,weather conditions, and the like. In general, a broad growth-inhibitingeffect is obtained with rates of from 0.5 to 20 pounds or more of activeagent per acre, and preferably with rates of from to pounds or more, andsuch rates are suitable and effective for control of vegetative growthon fallow land. When it is desired to obtain a selectivegrowth-inhibiting effect on weeds in areas containing crop plants suchas corn, soybeans, and cotton, rates of from 0.5 to 10 pounds generallygive good results. The Z-piperidino compounds disclosed and claimedherein as new compounds generally give selective growth inhibition, inpreemergent application, at rates of from 5 pounds, and preferably atrates of from 7.5 pounds and higher per acre; postemergent activity withthese compounds is exhibited at rates as low as 1 pound and lower, withsome selectivity. When in the typical mode of operation, the activeagent is employed as a composition comprising the agent, the exactconcentration of active agent in the composition is not critical, exceptthat the concentration and total amount of formulation employed beadequate to supply the appropriate amount of active agent on a per acrebasis. In general, good results are obtained when employing formulationscontaining the active agent in a concentration of from 0.5 to 10 percentor higher, in the instance of a liquid formulation; and in aconcentration of from 1.0 to 5.0 percent or higher, in the instance of adust, powder, granule, or the like. More concentrated formulations canbe prepared and are often preferred in that they can serve, dependingupon the particular application contemplated and the particularconcentration, both as a concentrated formulation for purposes ofshipment, storage, and the like, and as an ultimate treatingcomposition. A preferred composition comprises a surface active agent,an inert finely-divided solid and the present active agent, the activeagent being present in an amount of from 0.5 to 99.5 percent, by weight.

The expression surface active dispersing agent, as herein employed, isintended to include all agents which are capable of acting at theinterfacial surface between the active agent and water or other liquidmedium, facilitating thereby the dispersion of the agent in the medium.The term is inclusive of solid emulsifying agents such as finely-dividedbentom'te, pyrophyllite, fullers earth, attapulgite, silica, otherclays, and mineral carriers as well as liquid wetting and dispersingagents.

The term inert finely-divided solid, as herein employed, refers tomaterials whose primary function is not as dispersant of the activeagent in a liquid medium but as carrier for dust compositions.Representative such materials are chalk, talc, gypsum, powdered walnutshells, etc.

Liquid compositions containing the desired amount of active agent areprepared by dissolving the substance in an organic liquid or bydispersing the substance in water with or without the aid of a suitablesurface active dispersing agent such as an ionic or non-ionicemulsifying agent. Such compositions can also contain modifyingsubstances which serve as a spreader and sticker on plant foliage.Suitable organic liquid carriers include the agricultural spray'oils andthe petroleum distillates such as diesel fuel, kerosene, fuel oilnaphthas and Stoddard solvent. Among such liquids the petroleumdistillates are generally preferred. The aqueous compositions cancontain one or more water immiscible solvents for the toxicant compound.In such compositions, the carrier comprises an aqueous emulsion, e.g., amixture of water, emulsifying agent and water immiscible solvent. Thechoice of dispersing and emulsifying agent and the amount thereofemployed is dictated by the nature of the composition and by the abilityof the agent to facilitate the dispersion of the active agent in thecarrier to produce the desired composition. Dispersing and emulsifyingagents which can be employed in the compositions include thecondensation products of alkylene oxides with phenols and organic acids,alkyl aryl sulfonates, polyoxyalkylene derivatives or sorbitan esters,complex ether alcohols and the like. For a review of known surfaceactive agents which are suitably employed in implementing the presentinvention, attention is directed to U.S. 3,095,299, second column, lines25-36, and references there cited.

In the preparation of dust compositions, the active ingredient isintimately dispersed in and on a finely-divided solid such as talc,chalk, gypsum, and the like. In one method of achieving such dispersion,the finely-divided carrier is mechanically mixed or ground with theactive agent.

Similarly, dust compositions containing the toxicant compounds can beprepared with various of the solid surface active dispersing agents,such as bentonits, fullers earth, attapulgite, and other clays.Depending upon the proportions of ingredients, these dust compositionscan be employed as concentrates and subsequently diluted with additionalsolid surface active dispersing agents or with chalk, talc, or gypsumand the like to obtain the desired amount of active ingredient in acomposition adapted to be employed for the suppression of the growth ofthe plants. Also, such dust compositions can be dispersed in water, withor without the aid of a dispersing agent, to form spray mixtures.

Formulations containing the present active agent are oftenadvantageously further modified by incorporation therein of an effectiveamount of a surfactant which facilitates the dispersion and spreading ofthe formulation on the plant leaf surfaces and the incorporation of theformulation by the plant.

In accordance with the present invention, the active agent can bedispersed in soil or other growth media in any convenient fashion.Applications can be carried out by simply mixing with the media, byapplying to the surface of soil and thereafter dragging or discing intothe soil to the desired depth, or by employing a liquid carrier toaccomplish the pentration and impregnation. The application of spray anddust compositions to the surface of soil, or to plant parts or the aboveground surfaces of plants can be carried out by conventional methods,e.g., powder dusters, boom and hand sprayers and spray dusters, whethersurface or air-borne.

In a further method, the distribution of the active agent in soil can beaccomplished by introducing the agent in the water employed to irrigatethe soil. In such procedures, the amount of water is varied with theporosity and water holding capacity of the soil to obtain a desireddepth of distribution of the agent.

In addition, the present method also comprehends the employment of anaerosol composition containing one or more of the present active agentsas an active compound.

- 7 Such a composition is prepared according to conventional methodswherein the agent is dispersed in a solvent, and the resultantdispersion mixed with a propellant in liquid state. Such variables asthe particular agent to be used and the nature of the vegetation whichis to be treated will 5 determine the desirability of the solvent andconcentration of the agent therein. Examples of suitable solvents arewater, acetone, isopropanol, and Z-ethoxyethanoL- Satisfactory resultsare obtained when the active agent of the present invention, or acomposition comprising such active agent, is combined with otheragricultural materials intended to be applied to plants, plant parts, ortheir habitats. Such materials include fertilizers, fungicides,insecticides, other herbicides, soil conditioning agents, and the like.15

Where the present compounds are to be employed for selective weedcontrol in corn, a particularly preferred formulation is one whichcomprises the present active agent in a solution of nitrogen, with,optionally, other adjuvants also present. The nitrogen solution servesas a fertilizer for the corn crop, but also is initially effective as acontact herbicide. Inasmuch as the contact herbicidal action is notselective, such a nitrogen solution is applied as a directed spray toavoid or limit crop damage. Typically, such nitrogen solutions containfrom about 26 to about 32 percent nitrogen as ammonium nitrate, ammoniumsulfate, urea, and other nitrogen-containing compounds, and are appliedat such rates as to provide 90 pounds of nitrogen per acre.

While the compounds to be employed as active agent in accordance withthe present invention give good herbicidal results when employed alone,there are circumstances where it is desirable to employ one or more ofthe present compounds in combination with one or more other known,herbicides. For example, a combination of one of the present compoundswith a known herbicide may yield a herbicidal product which is lessexpensive, as for largescale herbicidal purposes, than sole use of thepresent compound would be-with the combination being equally effective.In addition, there are circumstances where the herbicidal activity of acompound of the present invention complements that activity of a knownherbicide, making a combination of the two substances particularlydesirable 45 from the standpoint of the herbicidal results obtained.

The identity of the known herbicide with which one or more of thepresent compounds is combined is not critical. Representative knownherbicides with which a compound of the present invention can becombined include, for example, those known herbicides listed in theHerbicide Handbook of the Weed Society of America (W. F. Humphrey Press,Inc., Geneva, N.Y., 1967); however, others can also be used.

Moreover, while the particular known herbicides with which a presentcompound or compounds is combined is not critical, a particularlypreferred combination is that of 1) One or more of the compounds to beemployed as active agent in accordance with the present invention; and

(2) A phenoxy or substituted phenoxyalkanoic acid of the formula:

agfiwat a,

Preferred phenoxy or substituted phenoxyalkanoic acids are2,4-dichlorophenoxyacetic acid: YY i and its salts and estersiand2-methyl-4-chlorophenoxyacetic acid: Y

and its salts and esters.

The identity of the salt or ester, when such derivative form isemployed, is not critical. In general, the salt or ester moiety isselected to confer higher water solubility or other desirable propertieson the substance. Representative and suitable salts and estersincludethe alkali metal, ammonium, trimethylammonium alkylamine, which can bemonoalkylamine, dialkylamine, or trialkylamine, alkanolamine which canbe monoalkanolamine, dialkanolamine, or trialkanolamine, salts, and thealkyl, alkoxyalkyl, and alkenyl esters. Others, of course, can be used.\Preferred alkylamine or alkanolamines are those containing less thanabout 25 carbon atoms. Representative such amines include methylamine,ethylamine, diethylamine, trimethylamine, rnonoethanolamine,triethanolamine, isopropanolamine, n-hexylamine, morpholine,dimethylamine, N-allyl- 1,3-propylenediamine. Preferred esters are thosein which the ester moiety contains not more than about 25 carbon atoms;and yet more preferred are those containingnot more than about 10 carbonatoms.

Representative phenoxy and substituted phenoxyalkanoic acid compounds tobe employed in such combinations include the following: 1 Y

2,4-dichlorophenoxyacetic acid isooctyl 2,4-dichlorophenoxyacetatemorpholine salt of 2,4-dichlorophenoxyacetic acid2,4,S-trichlorophenoxyacetic acid isooctyl 2,4,5-trichlorophenoxyacetatemethyl 4-chlorophenoxyacetate n-butoxy-n-propyl2,4-dichlorophenoxyacetate trimethylamine salt of2,4-dichlorophenoxyacetic acid n-butyl 4-(4-chlorophenoxy)butyrate ethyl2-(4-chlorophenoxy)propionate 2,4-dichlorophenoxyacetic acid, sodiumsalt 2,4,S-trichlorophenoxyacetic acid, potassium salt triethanolaminesalt of 2,4-dichl0rophenoxyacetic acid 2-methyl-4-chlorophenoxyaceticacid allyl2-methyl-4-chlorophenoxyacetate 2(2,4,5-trichlorophenoxy)acetic acid N-allyl-1,3-propylenediamine salt of2,4-dichlorophenoxyacetic acid Y isooctyl 2- (2,4,5 -trichlorophenoxy)propionate 2-(2,4-dichlorophenoxy)propionic acid isooctyl 2-2,4-dichlorophenoxy) propionate n-hexylamine salt ofZ-methyl-4-chlorophenoxyacetic acid 4-(2,4-dichlorophenoxy)butyric acidn-hexyl 4-(2,4-dichlorophenoxy)butyrate 4- (2-methyl-4-chlorophenoxy)butyric acid n-hexyl 4-(2,4,5-trichlorophenoxy)butyrate 4-(2-methyl-4-chlorophenoxy butyric acid n-hexyl 4-(2,4,5-trichlorophenoxy)butyrate 2,4-dichlorophenoxyacetic acid,ammonium salt trimethylamine salt of 2-methyl-4-chlorophenoxy aceticacid. Y

Such phenoxy or substituted phenoxyalkanoic acids can also be employedas the corresponding anilide. Thus, for example, the compounds of thepresent invention can also be employed jointly with compounds such as2-(2- methyl-,4-chlorophenoxy)-- m .(trifluoromethyDacetanilide and 2-(2 methyl 4 chlorophenoxy)-o-chloroacetanilide. In addition, theactiveagent of the present invention is advantageously" combined withsubstituted benzoic. acid and benzonitrile. herbicides, such as, forexample, 3-amino-2,5-dichlorobenzoic acid, 2,5-dichloro- 3 nitrobenzoicacid, Z-m'ethoxy-3,6-dichlorobenzoic acid, 2-rnethoxy-3,5,6--trichlor0benzoic acid, and 2,6-dic'hlorobenzonitrile. Furthermore, theactive agent of the present inventioncanbecombinedwith-yet other knownherbicides, such as, for example, 4-aminc-3,5,6-trichlorpicolinic acidor its salts or other derivatives.

The following examples illustrate the present invention.

EXAMPLE 1 Various of the compounds to be employed as active agent inaccordance with the present invention were evaluated for pre-emergentapplication to various species of plants. In this evaluation, a soil wasprepared consisting of one part masonry sand and one part shredded topsoil blended together in a cement mixer. One gallon of this soil wasplaced in a 25 x 35 cm. galvanized flat and was patted down with abench'brush until level. A three-row marker was used to make 2 /2 cm.deep furrows in approximately two-fifths of the flat. Crop seedsconsisting of four kernels of corn, five cottonseeds and five soybeanseeds were placed in these furrowsfA four-row template was then placedon the remaining soil and the indicated amounts of each of the,followingseeds were planted, one species to each section: foxtail(millet), 100 mg.; broad-leaf mustard, 50-75 mg.; rough pigweed, 30-50mg.; and large crabgrass, 350-400 mg.

Sufficient soil was added to cover the entire flat. Thus, theweed seedswere covered to a'depth of about 6 mm. and the crop plant seedsweref'coveredto a depth of about 3 'r',

In assaying the effect of the. composition as preemergent herbicides, aflat prepared as above, taken either on the day of planting or on thenext day, was placed in a chamber equipped with a turntable and an air.exhaust. The herbicidal composition, either a spray-type emulsion or awettable powder, was applied to the flat with a modified De Vilbissatomizer hooked to an air source. Twelve and one-half ml. of thecomposition under test were applied to each flat either on the day ofplanting or the succeeding day. Injury ratings and observations as totype of injury were made eleven to twelve days after treatment. Theinjury rating scale used was as follows:

0no injury 1-slight injury 2-moderate injury 3-severe injury 4death Whenmore than one determination was carried out, an average value wascalculated for the injury rating. Each compound evaluated was formulatedas a spray by one of the following procedures. In one method, theparticular compound was Wetted by grinding in a mortar with one part ofpolyoxyethylene sorbitan monolaurate. Five hundred parts of water wereadded slowly to the resultant creamy paste to give an aqueous dispersionwith a surfactant concentration of 0.2 percent. This dispersion wasentirely satisfactory for spray application. In a second procedure thecompound was dissolved in one volume of acetone, and the acetonesolution was diluted with nineteen volumes of water containing 0.1percent of polyoxyethylene sorbitan monolaurate.

In the following table setting forth the results of the evaluation,column 1 gives the name of the compound under test; column 2, the ratein pounds per acre at which the compound was applied to the test flat;and the remaining columns, the injury to the particular plant seeds orseedlings as measured by the foregoing scale.

JTABLE I.-IN.TURY RATING ON PREEMERGENT TREATMENT LbsJ Soy- Crab- Mus-Pig- Foxtail Velvet Compound acre Corn Cotton beans grass tard weedmillet leaf Z-hydroxY-Ii-phenylquinoxaline 8 0 0 0 2 3 4 22-chlor0-3-phenylquinoxaline 8 0 0 0 3 4 4 3 2 4 0 0 0 3 3 4 3 1 2 0 0 02 2 4 2 0 1 0 0 0 1 1 3 1 0 2(dipropylamino)-3-phenylquinoxaline 8 0 1 14 4 3 4 0 1 1 4 3 2 2 0 0 0 4 3 1 2-ethoxy-3-phenylquinoxaline 8 0 0 0 44 3 4 0 0 0 4 2 1 2-hydroxy-7-methyl-3-pheny1quinoxa1ine 8 0 0 0 4 3 32-hydroxy-fi-methylfl-phenylquinoxaline 8 0 0 0 4 3 36-0hloro-2-hydroxy-3-phenylquinoxaline 8 0 0 0 4 3 3 7-cl1loro-2-h drox-3- hen l uinoxaline 8 0 0 0 4 3 3 y y p y q 2 0 0 0 4 2 1 l-meth 1-3-hen 1-2- 1H uinoxalone 8 1 0 0 4 4 3 y p y q 4 0 1 0 4 4 3 2 0 0 0 4 4 32-methox -3- hen l uinoxaline 8 1 0 (l y p yq 4 0 0 0 3 l 1 0 l-nro l-3-hen l-2-1H uinoxalone 8 0 0 0 2 4 4 0 p Dy p y q 4 0 0 1 3 1 4 3 1 2 0 01 2 0 2 2 1 211- ro 0x -3- hen l uinoxaline 8 0 0 0 2 4 4 1 p p y p y q4 0 0 1 3 1 4 3 1 2 0 0 0 2 0 2 2 1 2-umino-3-phenylquinoxaline 8 0 0 04 4 3 4 0 0 0 4 2 2 2 0 0 0 4 1 0 2-piperidino-3-phenylquinoxaline 8 0 01 4 2 0 EXAMPLE 2 Representative compounds of the present invention WEEDCONTROL RATING were evaluated for post-emergent application to plants.Injury rating The evaluation was carried out 1n accordance w1th theGrasses Pigweed Crops (an PH) procedures of Example 1 except that thetest solutions Lb I PH SS P I were applied about 9-12 days after thepreparation and am P Sorghum Swbeans seeding of the flats. The resultsare as set forth in the fol- 8 7-0 9.0 10.0 10.0 4 v o 0 4 6.0 9.5 9.010.0 0 0 0 lowing table.

TABLE IL-INJ'URY RATING ON POST-EMERGENT TREATMENT Lbs./ Soy- Crab- Mus-Pig- Foxtail Compound acre Corn Cotton beans grass tard weed millet2-chloro-3-phenylquinoxaline 8 1 2 1 3 4 4 2 2-amino-3-phenylquinoxaline8 0 0 2 3 3 1 2 4 0 1 2 2 1 1 1 2-piperidino-3-phenylquinoxaline 8 2 2 22 4 2 2 4 2 2 2 3 4 3 4 2 1 1 1 2 4 3 2 1 1 0 1 2 4 2 2 EXAMPLE 3 Iclaim:

2-chloro-3-phenylquinoxaline was evaluated under field conditions. Inthis evaluation, field plots were prepared in routine fashion and anumber of the plots divided into two portions. One portion of each plotwas seeded with foxtail and crabgrass (grasses); the other portion wasseeded with pigweed. Other plots were seeded with corn, sorghum, andsoybeans, and yet other plots were set aside as control plots. In theinstance of the plots seeded with grasses and pigweed, treatment was byway of incorporation in the soil immediately preceding the seeding inthe instance of one-half of each portion of such plot; in the instanceof the other half, treatment was by means of a surface spray applicationimmediately after seeding. In the instance of the plots seeded to cropplants, application was exclusively by means of pre-plant incorporation.All plots were then held under good growing conditions for a period ofseveral weeks, at which time readings were made of the degree ofcontrol.

The results of the evaluation are set forth in the following table,where herbicidal activity is rated from 0-10, 0 indicating no herbicidalelfect, and 10 indicating a killing of the vegetaton in question. PPI isused to indicate application by pre-plant soil incorporation, and SS toindi- 1. The compound ofthe formula 1 I References Cited UNITED STATESPATENTS 3,453,365 7/1969 nae et a1 260-250R NICHOLAS S. RIZZO, 7 PrimaryExaminer P0-1050 UNITED STATEs PATENT hmhh CERTIFICATE OF CORREUHGNPatent No. 5,6 WJ95 Dated March 7, 1972- InventoI-(B) Quentin FrancisSoper It is certified that error appears in the above-identified patentI and that said Letters Patent are hereby corrected as shown below:

an In column 1, lines about 58-65, that portion of the formula.

reading should be Rn v n .[n column '2, lines 26-55, that portion of theright-hand formula reading loweralkyl loweralkyl N v 0 should be T oalso in column 2, line 61, the first word unit, "quinoxline",

should be --quinoxaline--.

In column 5, line 56, "2chloro-5-phenyliquinoxaline hydrochloride"should be -2-chloro-5phenylquinoxaline hydrochloride-- In column 6, line58, "bent onitsl' should be -bentonite--; also, in column 6, line 61,"pentration" should be -penetration-- .[n column 7, line 56,"herbicides" should be -herbicide-.

In column 8, line 2 1-, "trimethylammonium" should be followed by acomma.

in column 9, line 12, "trichlorpicolinic" should be -trichloropicolinic.

(5/69) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.5; +T,795 Dated March 7; 97

lnventoz-(s) Quentin Francis Sope'r It is certified that: error appearsit the above-identified patent and that said Letters Patent are herebycorrected as shown below:

At column 12, lines about 27-51, that portion of the formula reading TY] should be Signed and sealed this 7th day of November 1972,

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

